Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 2171:

  The best treatment for a student who accidentally poured conc tetraoxosulphate(vi) on his skin in the laboratory is to wash his skin with?

  Options:
  A) with cool running water
  B) sodium hydroxide solution
  C) iodine solution
  D) sodium trioxonitrate(v) solution
  Show Answer
  The correct answer is A .
• Question 2172: Copper (II) tetraoxosulphate (IV) is widely used as a? Options:
  A) fertilizer
  B) fungicide
  C) disinfectant
  D) purifier
  Show Answer
  The correct answer is B .
• Question 2173: The noble gas, argon, is used for Options:
  A) electrical arc welding
  B) welding brass
  C) underwater welding
  D) steel-welding
  Show Answer
  The correct answer is A .
• Question 2174: A certain industrial process is represented by the chemical equation 2A_(g) + B_(g) $\to$ C_(g) + 3D_(g) $\mathrm{\Delta }$H = X kJmol^-1. Which of the following conditions will favour the yield of the products? Options:
  A) increase in temperature, decrease in pressure
  B) increase in temperature, increase in pressure
  C) decrease in temperature,increase in pressure
  D) decrease in temperature, decrease in pressure
  E) constant in temperature, increase in pressure
  Show Answer
  The correct answer is A .
• Question 2175: Which of the following organic compounds is very soluble in water? Options:
  A) CH₃COOH
  B) C₂H₂
  C) C₂H₄
  D) CH₃COOC₂H₅
  Show Answer
  The correct answer is A .
• Question 2176: Suitable reagents for the laboratory preparation nitrogen are? Options:
  A) sodium dioxonitrate (III) and ammonium chloride
  B) sodium dioxonitrate (V) and ammonium chloride
  C) sodium chloride and ammonium chloride
  D) sodium chloride and ammonium diozonitrate (III)
  Show Answer
  The correct answer is A .
• Question 2177: 90.0g of MgCI₂ was placed in 50.0cm³ of water to give a saturated solubility of the salt is 8.0 mol dm³ at the same temperature, what is the mass of the salt left undissolved at the given temperature?(Mg = 24, Cl = 35.5) Options:
  A) 52.0g
  B) 58.5g
  C) 85.5g
  D) 88.5g
  Show Answer
  The correct answer is A .
• Question 2178: Sieving is a technique used to separate mixtures containing solid particles of Options:
  A) small sizes
  B) large sizes
  C) different sizes
  D) the same size
  Show Answer
  The correct answer is C .
• Question 2179: Which of the following statements is true about 2-methylpropane and butane Options:
  A) They have different number of carbon atoms
  B) They are members of same homologous series
  C) They have the same boiling points
  D) They have the same chemical properties
  Show Answer
  The correct answer is D .
• Question 2180:

  Which type of salt is found in antacid medications and is used to relieve heartburn and indigestion?

  Options:
  A) Aluminum chloride
  B) Magnesium chloride
  C) Sodium chloride
  D) Calcium chloride
  Show Answer
  The correct answer is B .